Continuous casting apparatus with movable ladles and tundishes

ABSTRACT

APPARATUS FOR CONTINUOUS CASTING OF METAL INCLUDING A PAIR OF LADLE-SUPPORTING CARRIER ARMS PIVOTALLY MOUNTED ON A COMMON VERTICAL ARBOR BETWEEN A COMMON LADLE RECEIVING POSITION AND A PAIR OF POURING POSITIONS. A PAIR OF TUNDISHES ALSO ARE PROVIDED, EACH SEPARATELY PIVOTABLE ABOUT ITS OWN VERTICAL SUPPORT BETWEEN A CASTING POSITION BENEATH A LADLE WHEN IN ONE OF THE POURING POSITIONS, AND AN INACTIVE POSITION. THUS, EACH TUNDISH, WHEN IN ITS CASTING POSITION, CAN RECEIVE THE OUTPUTS OF LADLES CARRIED BY EITHER OF THE CARRIER ARMS. AS ONE LADLE IS EMPTIED, THE LADLE ON THE OTHER CARRIER ARM IS BEING REPLACED WITH A FULL LADLE AND MOVED INTO POURING POSITION OVER THE TUNDISH, THEREBY ENABLING CONTINUOUS CASTING. PROVIDISONS ARE MADE FOR READY CLEANING AND REPLACEMENT OF THE TURNDISHES.

Jan. 5, 1971 r SCHQFFMANN ETAL 3,552,902

CONTINUOUS (;ATING APPARATUS WITH MOVABLE LADLEs AND TUNDISHES Filed Jan. 29, 1968 6 Sheets-Sheet 1 FIG! INVENTORS Rub; sc Hb'Ff-MANN BY ANTON MUBERA Jan. 5, 1971 -R, N ETAL v 3,552,902

CONTINUOUS CASTING APPARATUS WITH MOVABLE LADLES AND TUNDISHES Filed Jan. 29, 1968 6 Sheets-Sheet 2 INVENTOR5 RuDoLF s c :48 FFMANN BY Aunw K 5 774612 A TToR/YEYS' Jan. 5, 1971 5H6FFMANN ETAL 3,552,992

CONTINUOUS (TASTING APPARATUS WITH MOVABLE LADLE'S AND 'runnrsHfif Filed Jan. 29, 1968 6 SheetsSheet 5 INVENTORS .R DOLF SCH6FFMHNN BY ANTON ((uesRA *ruua ATTORNEY 'R. SCHOFFMANN ETAL 3,552,902 CONTINUOUS CEASTING APPARATUS WITH MOVABLE LADLES AND TUNDISHES Filed Jan. 29, 1968 Jan. 5, 1971 6 Sheets-Sheet 4 INVENTORS I fiuoeLc scolc'iFFMANN BY ANTON KUBERA "THEIK ATTORNEYS Jan. 5, 1971 R, SCHQFFMANN ETAL 3,552,902

cdn'rmuous CASTING APPARATUS WITH MOVABLE LADLES AND TUNDISHES 6 Sheets-Sheet 5 Filed Jan. 29. '1968 INVENTORS RUM: 5 c H3 FF MANN Aw-roN Kuseza day/ i 52, 4 DML 711602 AT'mgusYS Jan. 5, 1971 CONTINUOUS CASTING APPARATUS WITH MOVABLE LADLES AND TUNDISHES Filed Jan, 29, 1968 FIG-5.7

6 Sheets-Sheet 6 INVENTORS Eubou 5 H5FPMH N N A/v-rorv [406528 I 'msuz A'r-ramws rs United States Patent Oflice 3,552,902 Patented Jan. 5, 1971 3,552,902 CONTINUOUS CASTING APPARATUS WITH MOVABLE LADLES AND TUNDISHES Rudolf Schiilfmaun and Anton Kubera, Linz, Austria,

assignors to Vereinigte Osterreichische Eisenund Stahlwerke Aktiengesellschaft, Linz, Austria, 21 company of Austria Filed Jan. 29, 1968, Ser. No. 701,408 Claims priority, application Austria, Feb. 6, 1967, A ,084/67 Int. Cl. B22d 11/10 US. Cl. 164-281 4 Claims ABSTRACT OF THE DISCLOSURE Apparatus for continuous casting of metal including a pair of ladle-supporting carrier arms pivotally mounted on a common vertical arbor between a common ladle receiving position and a pair of pouring positions. A pair of tundishes also are provided, each separately pivotable about its own vertical support between a casting position beneath a ladle when in one of the pouring positions, and an inactive position. Thus, each tundish, when in its casting position, can receive the outputs of ladles carried by either of the carrier arms. As one ladle is emptied, the ladle on the other carrier arm is being replaced with a full ladle and moved into pouring position over the tundish, thereby enabling continuous casting. Provisions are made for ready cleaning and replacement of the tundishes.

The invention relates to a plant for continuous casting of metals comprising two carrier arms pivotable around a vertical axis and each adapted to carry a casting ladle, and at least one tundish.

For a long time, efforts have been made to enable an uninterrupted operation of continuous casting plants. A pre-requisite is that the exchange of a discharged casting ladle for a charged one is carried out as quickly as possible and that the liquid metal contained in the tundish of the casting plant sufiices for bridging the interval caused by the exchange of casting ladles.

In order to fulfill this demand, a carrying device has been proposed, which comprises a column arranged outside the operating range of the plant and a beam rotatably mounted thereon, the two opposed ends of said beam being designed as carrying platforms, each of them adapted to carry one casting ladle. By 180 turns of the beam, the platform carrying the charged casting ladle is respectively moved to the casting position and the opposite platform to the preparatory position. While the ladle in the casting position is discharged, the empty ladle is lifted olf the opposite platform and replaced by a charged one, whereupon the process is repeated.

The working ability of the known plant depends upon the provision that no disorders occur particularly with regard to the tundish. When it becomes necessary to remove slag from the tundish, or when its lining is worn, operation has to be interrupted. Thus, a completely continuous casting is not possible with that plant. Other difiiculties may arise because the carrier arms of the carrying beam cannot be moved independently. It is not possible to move a ladle out of the casting position, while preparation on the opposite end of the carrying beam is not yet finished, and vice versa.

The present invention aims at avoiding these disadvantages and ditficulties and has as its object to provide a continuous casting plant which permits of a freer variation and combination of the processes of preparing and discharging the ladle and the tundish or tundishes than hitherto possible, and in which any troubles which may occur can be easily overcome without necessitating an interruption in the continuous operation of the whole plant. A further object of the invention is to allow the use of two ladles in the casting operation and to enable a rapid exchange of ladles.

The plant of the invention, which comprises two carrier arms pivotable around a vertical axis and each adapted to carry a casting ladle, and at least one tundish, is characterised in that the two carrier arms are independently pivotable from a starting position, the delivery position, in opposite directions to two operating positions and that, if desired, also the tundishes pertaining to the operating positions of the casting ladles are pivotable from a resting position to the casting position.

The delivery position and the two operating positions are preferably spaced around a circle, in the center of which the perpendicular pivot axis for the carrier arms is arranged, the pivoting range of each carrier arm extending over both operating positions, so that the latter are traversable by both ladles.

Other preferred characteristics of the plant according to the invention are that the tundishes are tiltable, that they are liftable and lowerable, and displaceable in longitudinal direction.

The subject matter of invention is illustrated in the drawing by way of an embodiment. FIG. 1 shows an elevational view of the carrying device according to the invention, FIG. 2 a ground-plan. FIGS. 3 to 8 illustrate the function of the plant, namely of the carrying device and the tundishes. FIG. 3 is an overall plan, FIG. 4 an elevation as viewed along line IV-IV of FIG. 3, and FIG. 5 an elevational view along the line VV of FIG. 3. FIGS. 6 and 7 show lateral views of a tundish in two different operating positions, and FIG. 8 is an elevational view along line VIIIVIII of FIG. 6.

FIGS. 1 and 2 show the main parts of the carrying device according to the invention, i.e. a central column 1, on which carrier arms 2 and 3 are mounted to be independently pivotable. As shown in FIG. 2, each carrier arm is fork-shaped and holds a casting ladle 4 and 5, respectively. The carrier arms are pivotable through an angle (in the embodiment shown this angle is somewhat greater than 240), namely carrier arm 2 from position A through position B to position C and back, as demonstrated by arrow u, and carrier arm 3 from position A through position C to position B and back, as demonstrated by arrow v. Position A is the delivery position, and positions B and C are operating positions.

FIG. 3, wherein the described parts of the plant have the same reference numbers, shows further characteristics of the invention. Tundishes 6 and 7, respectively, are assigned to the operating positions B and C, said tundishes being pivotable around stationary axes 8 and 9 by means of swivel drives 10 and 11, which may be operated hydraulically or by any other kind of mechanism. The pivoting range of the tundishes is indicated by arrows at and y; it extends respectively from a resting position R to the casting position G situated opposite to the delivery posiion A of the ladles.

In FIG. 4, the ladle 5 is shown on carrier arm 3 in the operating position C, while arm 2 with ladle 4 is in the delivery position A. Tundish 7 is pivoted to the casting position, its outlet v12 resting above casting mould 13.

In addition, FIG. 4 shows draining channels 14 and 15 leading to the emergency ladle 16 (FIG. 3). They serve for draining otf the liquid metal, when an emergency arises and when there is danger of the tundish 7 becoming overcharged.

FIG. 5 shows the tundish in a position remote from the casting position. As evident, it is displaceable in the longitudinal direction, i.e. forward and backward, by

means of a knee-lever 17, as indicated by the dash-anddot lines, thus rendering it possible to adjust the position of the tundish to various sizes of slabs, i.e. to correctly position the outlets of the tundishes in every case. Besides, the tundishes are liftable and lowerable by being mounted on a vertically displaceable hollow shaft or sleeve 24- surrouncling the pivot axis of the tundishes. Owing to the vertical displaceability of the tundish, access to the mould for removal of slag is considerably facilitated. Lowering the tundish bears the further advantage that during casting the outlet of the tundish can be placed immediately above the mould, whereby the kinetic energy of the pouring metal stream is diminished.

FIG. moreover shows a tilting device, comprising flexibly connected arms 18 and 19, one end of arm 18, which is provided with a roller 20, engaging with a guide means 21 on the underside of tundish 6. By means of this tilting device, the tundish 6 can be tilted, in the completely advanced and lifted position, to the position indicated by broken lines, in which position slag falls into the slag pot 22. The tilting axle of the tundish is designated by 23.

In FIG. 6, the tundish is shown in position R of FIG. 3, namely in lifted position. When the tundish is pivoted to this position, its lid 25 overlies the rail-shaped supporting means 26 and 27; when the tundish is then lowered, as shown in FIG. 7, the lid is held by the supporting means 26 and 27, and the tundish can be pivoted to the tilting position K for removal of slag and for replacement by another tundish.

The plant of the invention makes different ways of completely uninterrupted operation of a continuous casting plant possible, while leaving extensive freedom in the combination of different process steps and at the same time ensuring a high operational security. One of the possible working methods consists in that several ladles are successively teemed through the same tundish. In detail, this is carried out as follows: One tundish is in the casting position, the other in the tilting position K or resting position R. This situation is shown in FIG. 3. The carrier arm 3 with casting ladle 5 has been pivoted over the tundish 7, and ladle 5 is discharged. Carrier arm 2 is pivoted to the delivery position A and, some time before casting ladle 5 is empty, a charged casting ladle 4 is deposited on the carrier arm. Before teeming of ladle 5 is finished, the carrier arm 2 can be turned clockwise to approach carrier arm 3 up to a certain distance. As soon as casting ladle 5 is completely discharged, its plug 28 is closed, and the carrier arm 3 is moved to the unoccupied delivery position, where the empty casting ladle is lifted off by means of an overhead crane or the like. Ladle 4, which is in readiness upon carrier arm 2, has in the meantime been moved to operating position C, so that it is positioned above the tundish 7. Its plug 29 is then opened and discharging of ladle 4 begins. The tundish 7 must have a sufficient holding capacity for enabling maintenance of the continuous operation, i.e. the discharging time of the tundish must be longer than the time required for pivoting the ladies in and out of the operating positions. While casting ladle 4 is emptied, another charged ladle is deposited in the delivery position and the cycle starts afresh.

The described working method can be maintained for such a time as the ceramic parts of the tundish, i.e. the lining, the plugs and outlets, can bear the strain. In order to be independent thereof, operation of the plant according to the invention may be modified by teeming several ladles successively into the same tundishe.g. in operating position C, as previously described-and subsequently changing over to the second tundish. Before tundish 7 and the ladle 5, which is in the operating position C, are completely discharged, tundish 6 is pivoted to the casting position G and the next charged ladle is moved from the delivery position to the operating position B. When discharging of ladle 5 in the operating position C is finished, its plug 28 is closed and ladle 5 is moved to the delivery position A. The plug 29 of ladle 4 in the operating position B is opened, and charging of tundish 6 starts. When the tundish 7 is completely empty, its outlet stoppers are closed, while at the same time the outlet stoppers of tundish 6 are opened. Teem ing is continued by the ladle in operating position B, and an exchange of ladles between positions A and B is performed in the same manner as previously described for positions A and C.

A third possibility for operating the plant of the invention is that several ladles are alternately teemed first through the one and then through the other tundish. With this working method, tundish 7, e.g., is in casting position and ladle 5 is being discharged (FIG. 3). Before tundish 7 is empty, tundish 6 is pivoted to the casting position, and an exchange of ladles between positions A and B is carried out. After a predetermined sequence of ladles, operation is again transferred to the tundish 7 and to operating position C, followed by an exchange of ladles between delivery position A and operating position C. As in the previously described embodiment, a newly prepared tundish must, after each exchange, be placed upon the pivoting device.

When a tundish is taken out of operation, it is first movedin lifted positionto resting position R, where the lid is removed in the manner described in connection with FIGS. 6 to 8; the tundish is then pivoted to the tilting position K and-in lifted and advanced positionis tilted around tilting axle 23 for emptying out slag. The tundish is then tilted back, lifted off by hoisting means, and a newly prepared tundish is deposited. In lowered position, this tundish is pivoted to position R, then it is lifted, whereby its lid is taken up by the supporting means 26 and 27. The tundish is now ready for being again pivoted to the casting position. When a disorder in the plant occurs, e.g. when there are leaky plugs in the ladle or the tundish, these vessels can be discharged by way of draining channels 14 and 15 into the emergency ladle 16, as previously described. For this purpose, it is useful to provide the tundishes with overflow channels, as indicated by numeral 30 in FIG. 3. The draining channels also serve for receiving the bottom cold steel from the tundishes. To that effect, draining channel 15 is suitably movable. It is pushed under the outlet of the tundish, until a faultless pouring stream has formed, then it is pulled back and the usual discharging into the mould can take place.

What we claim is:

1. An apparatus for continuous casting of a metal in a casting mold, comprising a central vertical arbor, two carrier arms of equal length pivotably mounted on said arbor and independently movable in opposite directions from a common starting position to two operating positions spaced along a path concentric with said arbor, a plurality of casting ladles, each adapted to be supported by one of said carrier arms, two vertical members, spaced from each other and from said central vertical arbor, two tundishes each having an outlet and pivotably mounted on respective ones of said vertical members, said tundishes each being pivotable from a resting position to a casting position, said outlet being located above said casting mold when the tundish is in said casting position, and means for lifting and lowering said tundishes.

2. An apparatus as set forth in claim 1 wherein said central vertical arbor is arranged between and along a straight line with said two vertical members.

3. An apparatus as set forth in claim 1 wherein each of said tundishes is tiltable in a position remote from said casting position by a stationary tilting device disposed at said remote position, each of said tundishes including guide means on the underside thereof and said stationary tilting device comprising flexibly connected arms, one of said arms being provided on one end with a roller engaging with said guide means.

5 6 4. A plant as set forth in claim 1 wherein said tundishes FOREIGN PATENTS are displaceable in the longitudinal direction. 201,399 2/1966 Sweden 1644281 References I. SPENCER OVERHOLSER, Primary Examiner UNITED STATES PATENTS 5 R. S. ANNEAR, Assistant Examiner 2,218,171 10/1940 Junghans 16482UX 3,115,686 12/1963 Baier 164-337 US. Cl. X.'R.

3,344,847 10/1967 Beemer --164-281 164337 

